Action View URL Helpers

Provides a set of methods for making links and getting URLs that depend on the routing subsystem (see ActionDispatch::Routing). This allows you to use the same format for links in views and controllers.

Namespace

Module

Methods

Included Modules

Constants

BUTTON_TAG_METHOD_VERBS = %w{patch put delete}
 

This helper may be included in any class that includes the URL helpers of a routes (routes.url_helpers). Some methods provided here will only work in the context of a request (link_to_unless_current, for instance), which must be provided as a method called request on the context.
RFC2396_PARSER = defined?(URI::RFC2396_PARSER) ? URI::RFC2396_PARSER : URI::RFC2396_Parser.new
STRINGIFIED_COMMON_METHODS = { get: "get", delete: "delete", patch: "patch", post: "post", put: "put", }.freeze

Instance Public methods

button_to(name = nil, options = nil, html_options = nil, &block)

Generates a form containing a single button that submits to the URL created by the set of options. This is the safest method to ensure links that cause changes to your data are not triggered by search bots or accelerators.

You can control the form and button behavior with html_options. Most values in html_options are passed through to the button element. For example, passing a :class option within html_options will set the class attribute of the button element.

The class attribute of the form element can be set by passing a :form_class option within html_options. It defaults to "button_to" to allow styling of the form and its children.

The form submits a POST request by default if the object is not persisted; conversely, if the object is persisted, it will submit a PATCH request. To specify a different HTTP verb use the :method option within html_options.

If the HTML button generated from button_to does not work with your layout, you can consider using the link_to method with the data-turbo-method attribute as described in the link_to documentation.

Options

The options hash accepts the same options as url_for. To generate a <form> element without an [action] attribute, pass false:

<%= button_to "New", false %>
# => "<form method="post" class="button_to">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"/>
#    </form>"

Most values in html_options are passed through to the button element, but there are a few special options:

  • :method - Symbol of HTTP verb. Supported verbs are :post, :get, :delete, :patch, and :put. By default it will be :post.

  • :disabled - If set to true, it will generate a disabled button.

  • :data - This option can be used to add custom data attributes.

  • :form - This hash will be form attributes

  • :form_class - This controls the class of the form within which the submit button will be placed

  • :params - Hash of parameters to be rendered as hidden fields within the form.

Examples

<%= button_to "New", action: "new" %>
# => "<form method="post" action="/controller/new" class="button_to">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6" autocomplete="off"/>
#    </form>"

<%= button_to "New", new_article_path %>
# => "<form method="post" action="/articles/new" class="button_to">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6" autocomplete="off"/>
#    </form>"

<%= button_to "New", new_article_path, params: { time: Time.now  } %>
# => "<form method="post" action="/articles/new" class="button_to">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"/>
#      <input type="hidden" name="time" value="2021-04-08 14:06:09 -0500" autocomplete="off">
#    </form>"

<%= button_to [:make_happy, @user] do %>
  Make happy <strong><%= @user.name %></strong>
<% end %>
# => "<form method="post" action="/users/1/make_happy" class="button_to">
#      <button type="submit">
#        Make happy <strong><%= @user.name %></strong>
#      </button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"  autocomplete="off"/>
#    </form>"

<%= button_to "New", { action: "new" }, form_class: "new-thing" %>
# => "<form method="post" action="/controller/new" class="new-thing">
#      <button type="submit">New</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"  autocomplete="off"/>
#    </form>"

<%= button_to "Create", { action: "create" }, form: { "data-type" => "json" } %>
# => "<form method="post" action="/images/create" class="button_to" data-type="json">
#      <button type="submit">Create</button>
#      <input name="authenticity_token" type="hidden" value="10f2163b45388899ad4d5ae948988266befcb6c3d1b2451cf657a0c293d605a6"  autocomplete="off"/>
#    </form>"
📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 296
      def button_to(name = nil, options = nil, html_options = nil, &block)
        html_options, options = options, name if block_given?
        html_options ||= {}
        html_options = html_options.stringify_keys

        url =
          case options
          when FalseClass then nil
          else url_for(options)
          end

        remote = html_options.delete("remote")
        params = html_options.delete("params")

        authenticity_token = html_options.delete("authenticity_token")

        method     = (html_options.delete("method").presence || method_for_options(options)).to_s
        method_tag = BUTTON_TAG_METHOD_VERBS.include?(method) ? method_tag(method) : "".html_safe

        form_method  = method == "get" ? "get" : "post"
        form_options = html_options.delete("form") || {}
        form_options[:class] ||= html_options.delete("form_class") || "button_to"
        form_options[:method] = form_method
        form_options[:action] = url
        form_options[:'data-remote'] = true if remote

        request_token_tag = if form_method == "post"
          request_method = method.empty? ? "post" : method
          token_tag(authenticity_token, form_options: { action: url, method: request_method })
        else
          ""
        end

        html_options = convert_options_to_data_attributes(options, html_options)
        html_options["type"] = "submit"

        button = if block_given?
          content_tag("button", html_options, &block)
        elsif button_to_generates_button_tag
          content_tag("button", name || url, html_options, &block)
        else
          html_options["value"] = name || url
          tag("input", html_options)
        end

        inner_tags = method_tag.safe_concat(button).safe_concat(request_token_tag)
        if params
          to_form_params(params).each do |param|
            inner_tags.safe_concat tag(:input, type: "hidden", name: param[:name], value: param[:value],
                                       autocomplete: "off")
          end
        end
        html = content_tag("form", inner_tags, form_options)
        prevent_content_exfiltration(html)
      end
🔎 See on GitHub

current_page?(options = nil, check_parameters: false, **options_as_kwargs)

True if the current request URI was generated by the given options.

Examples

Let’s say we’re in the http://www.example.com/shop/checkout?order=desc&page=1 action.

current_page?(action: 'process')
# => false

current_page?(action: 'checkout')
# => true

current_page?(controller: 'library', action: 'checkout')
# => false

current_page?(controller: 'shop', action: 'checkout')
# => true

current_page?(controller: 'shop', action: 'checkout', order: 'asc')
# => false

current_page?(controller: 'shop', action: 'checkout', order: 'desc', page: '1')
# => true

current_page?(controller: 'shop', action: 'checkout', order: 'desc', page: '2')
# => false

current_page?('http://www.example.com/shop/checkout')
# => true

current_page?('http://www.example.com/shop/checkout', check_parameters: true)
# => false

current_page?('/shop/checkout')
# => true

current_page?('http://www.example.com/shop/checkout?order=desc&page=1')
# => true

Let’s say we’re in the http://www.example.com/products action with method POST in case of invalid product.

current_page?(controller: 'product', action: 'index')
# => false

We can also pass in the symbol arguments instead of strings.

📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 550
      def current_page?(options = nil, check_parameters: false, **options_as_kwargs)
        unless request
          raise "You cannot use helpers that need to determine the current " \
                "page unless your view context provides a Request object " \
                "in a #request method"
        end

        return false unless request.get? || request.head?

        options ||= options_as_kwargs
        check_parameters ||= options.is_a?(Hash) && options.delete(:check_parameters)
        url_string = RFC2396_PARSER.unescape(url_for(options)).force_encoding(Encoding::BINARY)

        # We ignore any extra parameters in the request_uri if the
        # submitted URL doesn't have any either. This lets the function
        # work with things like ?order=asc
        # the behavior can be disabled with check_parameters: true
        request_uri = url_string.index("?") || check_parameters ? request.fullpath : request.path
        request_uri = RFC2396_PARSER.unescape(request_uri).force_encoding(Encoding::BINARY)

        if %r{^\w+://}.match?(url_string)
          request_uri = +"#{request.protocol}#{request.host_with_port}#{request_uri}"
        end

        remove_trailing_slash!(url_string)
        remove_trailing_slash!(request_uri)

        url_string == request_uri
      end
🔎 See on GitHub

Creates an anchor element of the given name using a URL created by the set of options. See the valid options in the documentation for url_for. It’s also possible to pass a String instead of an options hash, which generates an anchor element that uses the value of the String as the href for the link. Using a :back Symbol instead of an options hash will generate a link to the referrer (a JavaScript back link will be used in place of a referrer if none exists). If nil is passed as the name the value of the link itself will become the name.

link_to(body, url, html_options = {})
  # url is a String; you can use URL helpers like
  # posts_path

link_to(body, url_options = {}, html_options = {})
  # url_options, except :method, is passed to url_for

link_to(options = {}, html_options = {}) do
  # name
end

link_to(url, html_options = {}) do
  # name
end

link_to(active_record_model)

  • :data - This option can be used to add custom data attributes.

Because it relies on url_for, link_to supports both older-style controller/action/id arguments and newer RESTful routes. Current Rails style favors RESTful routes whenever possible, so base your application on resources and use

link_to "Profile", profile_path(@profile)
# => <a href="/profiles/1">Profile</a>

or the even pithier

link_to "Profile", @profile
# => <a href="/profiles/1">Profile</a>

in place of the older more verbose, non-resource-oriented

link_to "Profile", controller: "profiles", action: "show", id: @profile
# => <a href="/profiles/show/1">Profile</a>

Similarly,

link_to "Profiles", profiles_path
# => <a href="/profiles">Profiles</a>

is better than

link_to "Profiles", controller: "profiles"
# => <a href="/profiles">Profiles</a>

When name is nil the href is presented instead

link_to nil, "http://example.com"
# => <a href="http://www.example.com">http://www.example.com</a>

More concise yet, when name is an Active Record model that defines a to_s method returning a default value or a model instance attribute

link_to @profile
# => <a href="http://www.example.com/profiles/1">Eileen</a>

You can use a block as well if your link target is hard to fit into the name parameter. ERB example:

<%= link_to(@profile) do %>
  <strong><%= @profile.name %></strong> -- <span>Check it out!</span>
<% end %>
# => <a href="/profiles/1">
       <strong>David</strong> -- <span>Check it out!</span>
     </a>

Classes and ids for CSS are easy to produce:

link_to "Articles", articles_path, id: "news", class: "article"
# => <a href="/articles" class="article" id="news">Articles</a>

Be careful when using the older argument style, as an extra literal hash is needed:

link_to "Articles", { controller: "articles" }, id: "news", class: "article"
# => <a href="/articles" class="article" id="news">Articles</a>

Leaving the hash off gives the wrong link:

link_to "WRONG!", controller: "articles", id: "news", class: "article"
# => <a href="/articles/index/news?class=article">WRONG!</a>

link_to can also produce links with anchors or query strings:

link_to "Comment wall", profile_path(@profile, anchor: "wall")
# => <a href="/profiles/1#wall">Comment wall</a>

link_to "Ruby on Rails search", controller: "searches", query: "ruby on rails"
# => <a href="/searches?query=ruby+on+rails">Ruby on Rails search</a>

link_to "Nonsense search", searches_path(foo: "bar", baz: "quux")
# => <a href="/searches?foo=bar&baz=quux">Nonsense search</a>

You can set any link attributes such as target, rel, type:

link_to "External link", "http://www.rubyonrails.org/", target: "_blank", rel: "nofollow"
# => <a href="http://www.rubyonrails.org/" target="_blank" rel="nofollow">External link</a>

Rails 7 ships with Turbo enabled by default. Turbo provides the following :data options:

  • turbo_method: symbol of HTTP verb - Performs a Turbo link visit with the given HTTP verb. Forms are recommended when performing non-GET requests. Only use data-turbo-method where a form is not possible.

  • turbo_confirm: "question?" - Adds a confirmation dialog to the link with the given value.

Consult the Turbo Handbook for more information on the options above.

link_to "Delete profile", @profile, data: { turbo_method: :delete }
# => <a href="/profiles/1" data-turbo-method="delete">Delete profile</a>

link_to "Visit Other Site", "https://rubyonrails.org/", data: { turbo_confirm: "Are you sure?" }
# => <a href="https://rubyonrails.org/" data-turbo-confirm="Are you sure?">Visit Other Site</a>
📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 198
      def link_to(name = nil, options = nil, html_options = nil, &block)
        html_options, options, name = options, name, block if block_given?
        options ||= {}

        html_options = convert_options_to_data_attributes(options, html_options)

        url = url_target(name, options)
        html_options["href"] ||= url

        content_tag("a", name || url, html_options, &block)
      end
🔎 See on GitHub

Creates a link tag of the given name using a URL created by the set of options if condition is true, otherwise only the name is returned. To specialize the default behavior, you can pass a block that accepts the name or the full argument list for link_to_if.

<%= link_to_if(@current_user.nil?, "Login", { controller: "sessions", action: "new" }) %>
# If the user isn't logged in...
# => <a href="/sessions/new/">Login</a>

<%=
   link_to_if(@current_user.nil?, "Login", { controller: "sessions", action: "new" }) do
     link_to(@current_user.login, { controller: "accounts", action: "show", id: @current_user })
   end
%>
# If the user isn't logged in...
# => <a href="/sessions/new/">Login</a>
# If they are logged in...
# => <a href="/accounts/show/3">my_username</a>
📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 437
      def link_to_if(condition, name, options = {}, html_options = {}, &block)
        if condition
          link_to(name, options, html_options)
        else
          if block_given?
            block.arity <= 1 ? capture(name, &block) : capture(name, options, html_options, &block)
          else
            ERB::Util.html_escape(name)
          end
        end
      end
🔎 See on GitHub

Creates a link tag of the given name using a URL created by the set of options unless condition is true, in which case only the name is returned. To specialize the default behavior (i.e., show a login link rather than just the plaintext link text), you can pass a block that accepts the name or the full argument list for link_to_unless.

<%= link_to_unless(@current_user.nil?, "Reply", { action: "reply" }) %>
# If the user is logged in...
# => <a href="/controller/reply/">Reply</a>

<%=
   link_to_unless(@current_user.nil?, "Reply", { action: "reply" }) do |name|
     link_to(name, { controller: "accounts", action: "signup" })
   end
%>
# If the user is logged in...
# => <a href="/controller/reply/">Reply</a>
# If not...
# => <a href="/accounts/signup">Reply</a>
📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 414
      def link_to_unless(condition, name, options = {}, html_options = {}, &block)
        link_to_if !condition, name, options, html_options, &block
      end
🔎 See on GitHub

Creates a link tag of the given name using a URL created by the set of options unless the current request URI is the same as the links, in which case only the name is returned (or the given block is yielded, if one exists). You can give link_to_unless_current a block which will specialize the default behavior (e.g., show a “Start Here” link rather than the link’s text).

Let’s say you have a navigation menu…

<ul id="navbar">
  <li><%= link_to_unless_current("Home", { action: "index" }) %></li>
  <li><%= link_to_unless_current("About Us", { action: "about" }) %></li>
</ul>

If in the “about” action, it will render…

<ul id="navbar">
  <li><a href="/controller/index">Home</a></li>
  <li>About Us</li>
</ul>

…but if in the “index” action, it will render:

<ul id="navbar">
  <li>Home</li>
  <li><a href="/controller/about">About Us</a></li>
</ul>

The implicit block given to link_to_unless_current is evaluated if the current action is the action given. So, if we had a comments page and wanted to render a “Go Back” link instead of a link to the comments page, we could do something like this…

<%=
    link_to_unless_current("Comment", { controller: "comments", action: "new" }) do
       link_to("Go back", { controller: "posts", action: "index" })
    end
 %>
📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 390
      def link_to_unless_current(name, options = {}, html_options = {}, &block)
        link_to_unless current_page?(options), name, options, html_options, &block
      end
🔎 See on GitHub

mail_to(email_address, name = nil, html_options = {}, &block)

Creates a mailto link tag to the specified email_address, which is also used as the name of the link unless name is specified. Additional HTML attributes for the link can be passed in html_options.

mail_to has several methods for customizing the email itself by passing special keys to html_options.

Options

  • :subject - Preset the subject line of the email.

  • :body - Preset the body of the email.

  • :cc - Carbon Copy additional recipients on the email.

  • :bcc - Blind Carbon Copy additional recipients on the email.

  • :reply_to - Preset the Reply-To field of the email.

Obfuscation

Prior to Rails 4.0, mail_to provided options for encoding the address in order to hinder email harvesters. To take advantage of these options, install the actionview-encoded_mail_to gem.

Examples

mail_to "me@domain.com"
# => <a href="mailto:me@domain.com">me@domain.com</a>

mail_to "me@domain.com", "My email"
# => <a href="mailto:me@domain.com">My email</a>

mail_to "me@domain.com", cc: "ccaddress@domain.com",
         subject: "This is an example email"
# => <a href="mailto:me@domain.com?cc=ccaddress@domain.com&subject=This%20is%20an%20example%20email">me@domain.com</a>

You can use a block as well if your link target is hard to fit into the name parameter. ERB example:

<%= mail_to "me@domain.com" do %>
  <strong>Email me:</strong> <span>me@domain.com</span>
<% end %>
# => <a href="mailto:me@domain.com">
       <strong>Email me:</strong> <span>me@domain.com</span>
     </a>
📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 487
      def mail_to(email_address, name = nil, html_options = {}, &block)
        html_options, name = name, nil if name.is_a?(Hash)
        html_options = (html_options || {}).stringify_keys

        extras = %w{ cc bcc body subject reply_to }.map! { |item|
          option = html_options.delete(item).presence || next
          "#{item.dasherize}=#{ERB::Util.url_encode(option)}"
        }.compact
        extras = extras.empty? ? "" : "?" + extras.join("&")

        encoded_email_address = ERB::Util.url_encode(email_address).gsub("%40", "@")
        html_options["href"] = "mailto:#{encoded_email_address}#{extras}"

        content_tag("a", name || email_address, html_options, &block)
      end
🔎 See on GitHub

phone_to(phone_number, name = nil, html_options = {}, &block)

Creates a TEL anchor link tag to the specified phone_number. When the link is clicked, the default app to make phone calls is opened and prepopulated with the phone number.

If name is not specified, phone_number will be used as the name of the link.

A country_code option is supported, which prepends a plus sign and the given country code to the linked phone number. For example, country_code: "01" will prepend +01 to the linked phone number.

Additional HTML attributes for the link can be passed via html_options.

Options

  • :country_code - Prepends the country code to the phone number

Examples

phone_to "1234567890"
# => <a href="tel:1234567890">1234567890</a>

phone_to "1234567890", "Phone me"
# => <a href="tel:1234567890">Phone me</a>

phone_to "1234567890", country_code: "01"
# => <a href="tel:+011234567890">1234567890</a>

You can use a block as well if your link target is hard to fit into the name parameter. ERB example:

<%= phone_to "1234567890" do %>
  <strong>Phone me:</strong>
<% end %>
# => <a href="tel:1234567890">
       <strong>Phone me:</strong>
     </a>
📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 671
      def phone_to(phone_number, name = nil, html_options = {}, &block)
        html_options, name = name, nil if name.is_a?(Hash)
        html_options = (html_options || {}).stringify_keys

        country_code = html_options.delete("country_code").presence
        country_code = country_code.nil? ? "" : "+#{ERB::Util.url_encode(country_code)}"

        encoded_phone_number = ERB::Util.url_encode(phone_number)
        html_options["href"] = "tel:#{country_code}#{encoded_phone_number}"

        content_tag("a", name || phone_number, html_options, &block)
      end
🔎 See on GitHub

sms_to(phone_number, name = nil, html_options = {}, &block)

Creates an SMS anchor link tag to the specified phone_number. When the link is clicked, the default SMS messaging app is opened ready to send a message to the linked phone number. If the body option is specified, the contents of the message will be preset to body.

If name is not specified, phone_number will be used as the name of the link.

A country_code option is supported, which prepends a plus sign and the given country code to the linked phone number. For example, country_code: "01" will prepend +01 to the linked phone number.

Additional HTML attributes for the link can be passed via html_options.

Options

  • :country_code - Prepend the country code to the phone number.

  • :body - Preset the body of the message.

Examples

sms_to "5155555785"
# => <a href="sms:5155555785;">5155555785</a>

sms_to "5155555785", country_code: "01"
# => <a href="sms:+015155555785;">5155555785</a>

sms_to "5155555785", "Text me"
# => <a href="sms:5155555785;">Text me</a>

sms_to "5155555785", body: "I have a question about your product."
# => <a href="sms:5155555785;?body=I%20have%20a%20question%20about%20your%20product">5155555785</a>

You can use a block as well if your link target is hard to fit into the name parameter. ERB example:

<%= sms_to "5155555785" do %>
  <strong>Text me:</strong>
<% end %>
# => <a href="sms:5155555785;">
       <strong>Text me:</strong>
     </a>
📝 Source code 
# File actionview/lib/action_view/helpers/url_helper.rb, line 620
      def sms_to(phone_number, name = nil, html_options = {}, &block)
        html_options, name = name, nil if name.is_a?(Hash)
        html_options = (html_options || {}).stringify_keys

        country_code = html_options.delete("country_code").presence
        country_code = country_code ? "+#{ERB::Util.url_encode(country_code)}" : ""

        body = html_options.delete("body").presence
        body = body ? "?&body=#{ERB::Util.url_encode(body)}" : ""

        encoded_phone_number = ERB::Util.url_encode(phone_number)
        html_options["href"] = "sms:#{country_code}#{encoded_phone_number};#{body}"

        content_tag("a", name || phone_number, html_options, &block)
      end
🔎 See on GitHub